Electric Vehicles

This is a post I started 6 years ago and decided not to publish. Since then things have changed a lot so here goes.

The History of Electric Vehicles

The Electric Vehicle has been around for a long time. The new push to Electric Vehicles is mostly being pushed by the belief that they will reduce carbon emissions. This really depends on where the power comes from, how efficient the motors are and how well the batteries work. Most studies prior to 2011 have shown that unless a substantial amount of the power comes from renewable energy then it is likely the Electric Vehicle will generate more pollution than a petrol vehicle.

Electric Vehicles began a long time before the petrol vehicle was the norm and even way before Vanguard made the first mass produced Electric Vehicle in the 1970s.

So what happened to the Electric Vehicle? The challenge today is still the same, the Battery. We really need a better solution. Which is where my original post stopped.

Guess what? It seems to have happened.

Tesla et al

So enter Elon Musk and Tesla Motors. His purpose is to take petrol off the road so they have done some pretty innovative things including opening up their patent database so anyone can use their technology with their permission.

Tesla

And of course Nissan, Toyota, Honda and many others are putting Electric Vehicles front a center in their product lines now.

With improvements in energy density storage and reducing costs for high capacity batteries we are approaching a time when Battery Electric Vehicles are the better choice for the environment, even when charged with electricity derived from fossil fuels. Studies show that there are more Emissions from the manufacture of a Electric Vehicle, but this is made up for in 1 year of operating emissions improvements and over the course of the Electric Vehicle’s life, Global Warming Emissions are halved. This assumes a 50mpg (US based study) petrol vehicle is used for the comparison. This equates to 21.3Kpl or 4.7L/100Km so this is as realistic comparison with a high efficiency petrol or diesel vehicle.

What a big different 6 years makes.

Hydrogen Fuel Cell Cars

So how are Hydrogen Fuel Cell based cars progressing? Calculations are that it will be roughly 3 times less efficient that a Battery Electric Vehicle. And extracting the H2 also requires energy. So H2 is an energy storage source. It is hard to store and manage and so the infrastructure costs are also high. So it is hard to do. The plus is that you don’t consume any fossil fuels in the process if you use some of the new solar based extraction mechanisms so although there are big drawbacks, there are also big benefits. The following video covers the territory well including some commentary from Elon Musk toward the end.

Let’s look at another perspective which is more optimistic.

So the infrastructure just isn’t there. So it looks like Battery Electric Vehicles are still the way to go. But the advantages are big enough that the debate will continue. And it is interesting that we have multiple fuel types in use simultaneously including Petrol (gasoline), Diesel, LPG, Alcohol, Battery Electric, Hydrogen, Biodiesel, compressed air, coal, wood and others.

The big advantages for Hydrogen are:

longer operating range than battery alone but not as much as petrol/diesel/LPG

no harmful emissions when running, the same as Battery Electric Vehicles and a big improvement over petrol/diesel/LPG

Time will tell. I should put a diary entry into my calendar for 6 years time and do another comparison.

Powering Telemetry

A big issue in the world of the Internet of Things, or IoT as it is abbreviated, is how to get power to remote devices. And this splits up into 2 separate but definitely related problems:

the power source

the power consumption

Obviously, if the power consumption is high, the power source has to be capable of providing a lot more power. We looked at this in our IoT – Remote Telemetry Case Study. So let’s tackle that one first.

And the focus for this article is remote devices using Solar Charging. Before we look at that specifically, let’s understand the problem.

The short version of this is that you have to do 2 things at the same time:

reduce the average power that is consumed all the time

reduce the energy required to process an event

The first of these is also known as Quiescent Power Consumption. This is the power consumed just running the system when it is doing nothing, or close to it. At a minimum, the Power Supply has to deliver this amount of power just to make sure that we could react to an event, should it occur. And I can hear you thinking that it is hard to get this low enough and still have a responsive system.

Correct! But you have to have at least this amount of power or Game Over!

Which is where the second part comes in. You also need some power to respond to events. These can be something you need to log, or reports you need to post. If you are uploading to a web service using cellular communications, the peak power consumption can be very high. So you have to minimise this time.

We would normally model both of these and work out a power budget based on the worst case scenario model. Excel is a suitable tool for doing simple modelling of this as well as scenario modelling.

But I can hear you thinking “why worst case“? Answer: “Because you want it to always work, not just work on average“!

Telemetry

Telemetry means measurement at a distance or remote measurement. So you are measuring something at location A, and want to know the value of the measurement at location B. This implies the 2 locations are not close enough together that this is a trivial problem to solve.

In our world, Telemetry can mean anywhere on earth, though our customers are usually in Australia. In NASA’s world, (maybe world is the wrong term for them) it can be anywhere in the solar system. Voyager 1 is currently more than 18 billion Kilometers away and has been active for 40 years.

Artist’s concept of Voyager in flight

The challenge for low power consumption, is how to get the measurement from location A back to location B?

Solar Charging

The NASA solution is simple. Near sun facilities are Solar Powered, and the rest use some form of nuclear power. Since no-one will ever let us nuclear power any Telemetry device, and I’m Okay with that, and we are near enough to see some sun, we will follow that option instead. And besides which, we can do it in our office and not a heavily shielded facility.

So lets recap on what we know about solar charging:

ignoring the energy cost of making a solar panel, the energy cost is free after that

Not all Solar Panels are equal. If you want you panel to work in a mostly shady place then you might also want to use mono-crystalline Silicon solar cells because they are efficient and can continue to convert even low levels of light. In recent developments the efficiency of conversion had passed 25% as reported in Efficiency of Silicon Solar Cells Climbs and some of the stacked cell technologies are past 40% efficiency.

compact solar cell

And then you have to harvest that energy. Which is where new devices like the SPV1050 come in. Experiments in our office showed that we can charge a Lithium Polymer battery from the internal lighting. And it is a buck boost converter meaning that it can charge the battery in full sunlight (reducing voltage) and also moonlight (increasing voltage) and the device costs less that $2 in 1K pieces.

I only have on criticism. The super low quiescent current LDOs would have been more useful if they were fully independent because this would have taken another item off the Bill of Materials.

Primary Cells

The other option for Telemetry is using Primary Cells. These are not rechargeable and so must last the life of the product. We currently deploy Cellular based Telemetry modules that can run for up to 10 years from a Lithium Primary Cell or 5 years from Alkaline Primary Cells. This is ideal for Smart City style projects where the devices might be moved as they fulfill their current purpose. A good example of this is people metering or pedestrian counting where a council may want to know how much use an area is getting. Once that is understood, the Telemetry module can be redeployed and since it isn’t connected to mains power you don’t need an electrician to do that. Or they could be used to understand the level of demand of public transport services in real time so you can adjust capacity on the fly.

Putting Light to Work

Light is a really interesting thing. It has so many different aspects. And it took us a long time to work out exactly how it functioned. And in many ways that is still an ongoing process. So this post is a brief survey of some recent advances in our understanding of light, how to use it, and how to generate it.

Extracting Energy from Light

Recent advances in Quantum Dots have taken us one step closer to improving our extracting of energy from light and Solar Cells continue to improve.

The chart below is from the link above and shows that the fastest improving Solar Cell technologies (the 2 steepest red lines) are Perovskite Solar Cells and Quantum Dot Solar Cells. Click to get a larger version. Or go to the interactive link where you can get more detail for each dot.

Solar Cell Efficiencies – By Time And Technology

And for a good summary of PV (PhotoVoltaic) technologies the link below provides a useful guide.

So apart from turning the light in electricity, what else can we do with light?

Light for Communication

Light is also useful as a communications tool. And recent advances in Quatum Dot management of light means it could hold the key to higher levels of computing power in the future, as well as more secure communications.

LED Street Lighting

With concern for rising global emissions and the majority of the worlds power still generated by burning fuels of one kind of another, the replacement of older street lighting technologies with higher efficiency and longer life LED Street Lighting would appear to make sense. And on the up side, everyone agrees that the longer life of the LEDs compared to other lighting technologies is a huge plus.

Colour Temperature, or how warm or cold a light appears to our eyes, has a significant impact on how we perceive the lights. Above we see very white looking LED lighting alongside more traditional High Pressure Sodium lamps. The much bluer LED Street Lights cause several serious issues including:

actually reducing our ability to see clearly at night

disturbing noctural creatures more (eg. hatching turtles)

affecting sleep patterns

affecting biorythms

decreasing our ability to see stars at night

So the energy savings are real, but the environmental side affects are too.

Managing Colour Temperature

Unfortunately LEDs are not as easy to control for Colour Temperature. Unlike an incandescent light, they emit a very narrow band of wavelengths of light. And most White LEDs emit blue and use a phosphor to down convert some of the Blue to Yellow so they look whiter rather than Bluer. The earliest White LEDs were very blue and so early adopters of LED Street Lighting have ended up with the worst outcome. And the more we warm up the colour the lower the efficiency because we lose some energy in the down conversion.

The are some breakthrough underway and Cree have recently discovered that it is more efficient to add some red LEDs to the mix to drop the perceived colour temperature. And this is helping. But even the newest devices are at a colour temperature of 3000K and the High Pressure Sodium Lamps are at around 2100K. So still quite a bit different.

The only solution for the millions of already installed LED Street Lighting is unfortunately to swap them out for more recent LED arrays that are at a better colour temperature.

Batteries Today

There are 4 separate drivers for current battery technology:

Cost

Size and Weight

Capacity

Recharge rates and cycles

An example of an emerging industry for batteries is electric vehicles. These require high recharge rates, high capacity, high recharge cycles and acceptable weight, size and cost. So the current front runner in commercial batteries, the Lithium Ion battery, has some challenges meeting these requirements. But it is also the best we have right now.

Adding Super Capacitors

One approach to improving battery performance in peak demand situations is to add a Super Capacitor in parallel with a conventional lead acid battery. The Super Capacitor smooths the energy demand by delivering the high current needed for peak demand and the lead acid battery provides the bulk energy storage.

CSIRO UltraBattery Inventor – Dr Lan Lam

The CSIRO developed UltraBattery is a good example of Australian Technology Innovation in next generation batteries. It is one example of their work in Energy Storage. And also good example of their partnerships with industry to bring next generation technologies to commercial reality.

New Battery Technologies

The front runner for the next generation of battery technologies is the Lithium Air Battery. This promises double the energy density per unit volume of Lithium Ion Batteries but at 20% of the weight. So ideal for Electric Vehicles where weight is one of the critical elements.

Researchers believe commercial versions of this battery technology are only 10 years away. That isn’t that long for a new battery technology. The hurdles they still need to face are primarily in protecting the pollution from corroding the metal electrode and preventing dendrite growth which is an existing problem with Lithium Ion Batteries. The electrode wants pure oxygen and is corroded by moisture, carbon dioxide and nitrogen. So some challenges remain.

Using Existing Batteries Better

The other approach is the one we usually take. Use Existing Batteries Better. This involves better power management, better battery management and rethinking the whole solution to a problem. We showed an example in a recent Remote Telemetry Case Study we did in the Internet of Things space where we took an installation that would have required a 200W solar panel and instead deployed a system that runs from 4xAA batteries for 2 years. The next step is to add an energy harvesting component with a suitable rechargeable technology to take the battery maintenance interval from 2 years to 5 years. Even with the best and most durable rechargeable battery technology around today for regular commercial applications, a 5 year maintenance interval is still needed.

So multiple approaches. I’m looking forward to the next set of breakthroughs in this area. Including marrying the CSIROSuper Capacitors with a Lithium Air Battery.

Local versus global electrical power

Up until recently, AC Power Distribution was the most efficient way to move electrical energy about. But right back at the beginning of electricity, it wasn’t obviously the case. Thomas Edison had favoured DC voltage and current distribution but was defeated commercially by almost all other comers because the technology to do AC Voltage Transformation, the transformer, was just easier top make than a DC version based on the technology of the day.

Thomas Edison

You can read more about this era in the War of Currents. This was the 1880’s of course. Probably the highest fundamental invention decade so far. But that is for another post.

Modern DC Power Distribution

Wind forward more than 100 years and the technology to transform DC voltage and current, at high efficiency, is mainstream. Of course the incumbent AC infrastructure is wide spread and not easily displaced. But DC is winning ground in new installations.

In Australia, Basslink is connecting Tasmanian power generators to the Victorian electricity grid using HV/DC or High Voltage DC Technology. It is now the technically superior offering.

World Power Grid

And so the new opportunities open up for sharing power across the globe. The current plans are just for grid connect. But if you consider renewable energy as a major contributor, if we have a globally connected grid then the solar power generators sun side can be supplying the night side communities and 12 hours later the other way around. If solar goes global and the grid goes global, then the fluctuating and time of day dependent power generation can be balanced out globally. What we can’t make economic in a single region, can suddenly become overwhelmingly compelling across the globe.

That will require quite a lot of collaboration and market trading beyond what has traditionally been possible, but the pay off would prove worth it. I am going ahead of what we can currently do, but I also believe this is where we have to get to.

Internet of Things

The Internet of Things, or IoT as it is abbreviated to, is still an emerging trend. But it is driving some substantial changes in some industry areas. This includes the 4th Industrial Revolution, also known as Industry 4.0.

If you are deploying to a factory or industrial complex, then generally the networking and power is already dealt with and you can piggy back off the existing infrastructure. But what about deploying Remote Telemetry? If you wanted to measure water tank levels or water usage in a rural location you might have to use a solar powered or primary battery powered system and 3G or 4G communications to get the data back to a website or server. That can have its own challenges. The typical industrial computer used for these monitoring tasks and posting reports or transactions requires a lot of power to run and is expensive. So can you do it if the budget for the hardware is $600, you don’t want to use solar cells and also don’t want to change the batteries every month?

Victorian iAwards 2015

Last year at the Victorian iAwards 2014 , our client Rectifier Technologies Pacifictook out 2 categories for Victoria. This year we are pleased to have 2 clients as finalists and at the iAwards ceremony this evening they both took out merit awards for their category. A merit award means they were judged to be within 5% of the category winners and so also qualify for inclusion in the National iAwards.

iAwards VIC Merit

Sustainability

Rectifier Technologies Pacific received a Merit Award in the Sustainability category for the RT18 425V High Efficiency EV Charger Rectifier. This is an important technology breakthrough in high efficiency electric vehicle charging and we were pleased to see them received recognition for that. Software we developed for them is part of the product.

New Product

We are very pleased for Jason and Lynne who have had to persevere through a lot to get to this point. The combination of Bluetooth Smart, Qi Wireless Charging, 3G communications and GPS tracking in a device the surface area of a business card was a big technical challenge and deserved to be recognised.

Skynanny.net celebrate with Successful Endeavours and Zain Digital

Our congratulations also go to Zain Digital for their work in development of the App and Web Services that supports the product.

iAwards

The iAwards are an annual celebration of Innovation in driving economic growth in Victoria. This year we were pleased to see one of our clients, Rectifier Technologies Pacific, nominate for an award. They were encouraged to do so and I was pleased that they followed through on that encouragement.

iAwards Winners 2014

This was for their RT15 240V 100A HRE Rectifier. This is a high power level and high efficiency AC to DC Power Converter.

Rectifier Technologies Pacific

One of the reasons we are familiar with the product is that we did some of the core Embedded Software Development and know just how good the hardware design in the power stage is. You can get more information from Rectifier Technologies Pacific AC/DC Product Range.

So congratulations again to Rectifier Technologies Pacific and to all the rest of the winners at this year’s iAwards.

What if we could start again

In the days when DC converters didn’t exist, it made sense to base our electrical distribution system on transformers and AC voltage level shifting. It still makes sense to distribute at high voltage where resistive losses in the wires are a smaller issue than they are at lower voltages. But if we were starting again, what would that look like?

High Voltage Direct Current Transmission

Use High Voltage Direct Current, or HVDC, as the transmission standard. This is now possible whereas 100 years ago it was not. As much as anything this is a legacy issue. The electricity link between Tasmania and Victoria that runs under Bass Straight uses this technology for instance.

HVDC Distribution

Renewables at any level

And we would design it to cope with any level of Renewable Energy sources. This is one of the inhibiting factors for the use of fluctuating energy sources and traditionally it was considered that 8% was the maximum you could have. Germany recently showed this wasn’t the case with a German Renewable Power Contribution of 59%. There is still plenty of work to do but this is an example that some of the old paradigms are not absolute limits after all.

Renewable Energy Sources

Resilience

Another issue is the robustness or Resilience of the grid. This refers to the ability of the grid to recover from transients and faults. The Northeast Blackout of 2003 showed that a lack of Resilience is a major weakness. If you aren’t familiar with the incident then check out the following short video on what happened and wider implications for not having Resilience.

Regardless of the source of the issue, we have to be able to quickly isolate faults and not lose complete grid control. A Resilient grid is a must.

Communication

This is one of the things needed for Resilience. All generation and transmission facilities should be able to communicate so that the system can be coordinated. This is sometimes referred to as the Smart Grid and a lot of work has been done to create robust, widespread and secure communications to measure and control the operation of the Electricity Grid. One example is DNP3 which is widely used by Power Factor Correction Controllers, Reclosers, Sectionalisers, RTUs and control systems to monitor and manage the Electricity Grid.